Sayyid

A sayyid is a person patrilineally descended from the Prophet Muhammad's uncles al-Abbas and Abu Talib, or from one of the sons of his daughter Fatimah - Hassan ibn Ali and Husayn ibn Ali. Historically, most of the caliphs have been descended from Muhammad and his Quraysh tribe, with the Abbasid Caliphate claiming descent from al-Abbas while the Fatimid Caliphate descended from Fatimah.